So this morning I gut my gumption up, went to the orange big box, and bought all of the supplies i would need for this job. Called a good friend who is the director of maintenance for a school district, and he came over.
After much deliberating and head scratching we came to the conclusion that the only way to get to the pipes was to either take out the back seat, which is an electric fold down, or take out the water heater. There's just no room to get the tools in to either cut the pex or crimp it back. Both of those choices were a no. All is not lost however.
While messing with the broken valve, i noticed that the valve stem was sticking out in the back of the valve. I pushed it back into its normal position and found that there was plenty of stem left to use pliers to turn the valve either open or closed. So, at least I can get the winterizing done. For now, the bypass valves are in the correct position and the broken one is secured with a hose clamp to keep the stem from moving or pushing out of place.
If I could just find the stem with knob, I could fix this without taking out any pex tubing. I've google searched a ton and can't find a valve like I have or replacement parts. The numbers on the handle are : VI F877 PLS B137.5 F2159.
Edit: I may have found it!
https://www.supplyhouse.com/Viega-43...EX-Crimp-Valve
Does this look right?
I'm good for the winter, but I'll have to do something permanent in the spring.
Thanks again everyone for all of your help!